The present invention relates to a dishwashing machine, in particular a household dishwashing machine, having a box-shaped washing tank for receiving items to be washed, having a base carrier whereupon the washing tank is placed and having a technology space for accommodating electrical components of the dishwashing machine that is arranged between a base formed on the base carrier and the washing tank.
In practice, a household dishwashing machine comprises a box-shaped washing tank for instance which is arranged on a base carrier and is fastened hereto. The washing tank and the base carrier are arranged here in an exterior housing of the dishwashing machine. The box-shaped washing tank is preferably manufactured from a rust-resistant sheet metal, in particular a stainless steel panel and comprises a tank floor, two side walls, a rear wall and a roof element. It may alternatively, if necessary, also be composed of a U-shaped hood and a cover part or inserted part of the base carrier. A loading opening is provided on a front side of the dishwashing machine, which faces a user when the dishwashing machine is used conventionally, it being possible to close said loading opening by means of a moveable door. When the door is open, items to be washed can be introduced into the washing tank and/or washed items can be removed from the washing tank through the loading opening. By contrast, when the door is closed, an essentially closed dishwasher interior is produced inside the washing tank.
The dishes are cleaned when the door is closed, by rinsing water being applied to the items to be washed. To this end, a spray system is installed in particular in the washing tank, by way of which rinsing water with different temperatures can be sprayed into the dishwasher interior depending on the washing phase. As a function of the washing phase, detergent and/or additives are added to the rinsing water in order to be able to achieve a good washing and drying result.
While a dosing facility for the automatic addition of detergents and additives is preferably arranged for instance on an internal side of the washing tank or an internal side of the door, a technology space is provided for further components of the dishwashing machine, said technology space being arranged above a floor of the base carrier and below the washing tank. A circulating pump for feeding the spray system with rinsing water, a heating element for heating the rinsing water and a water switch, which is arranged between the circulating pump and the spray system, is usually found in the technology space, thereby intentionally providing individual spray elements of the spray system with rinsing water. A drain pump can also be provided in the technology space, said drain pump being used to pump off used rinsing water.
During operation of the dishwashing machine, the metallic washing tank is excited to vibrate by circulating rinsing water, said vibrations resulting in the emission of sound. In order to reduce sound emissions of this type, polymer-modified bitumen mats with an adjusted loss factor are adhered to the exterior of the washing tank. The adhered bitumen mats cause an additional mass to be applied to the thin sheet metal parts of the washing tank, thereby reducing their tendency to vibrate. Furthermore, the bitumen mats cause the vibrations to convert into heat as a result of internal friction. Nevertheless, the emission of airborne sound cannot be completely prevented by the bitumen mats.
During operation of the dishwashing machine, airborne sound is also generated and emitted by the electrical components of the dishwashing machine which are arranged in the technology space. In particular, electrically driven and/or electrically actuated components, such as in particular the drain pump, the circulating pump and/or the water switch, contribute to a sound generation of this type.
In order to reduce the outward propagation of the airborne sound which is produced in the region of the washing tank and in the region of the technology space, two-dimensional, in other words planar acoustic, components made of an absorption material are usually attached to the internal side of the exterior housing of the dishwashing machine. Acoustic components of this type are embodied as plates or mats with a minimal layer thickness and rest in a two-dimensional manner against the internal side of the exterior housing. They are therefore embodied as a thin layer and essentially feature the same layer thickness at each point of their plane. The plate-shaped acoustic components can be produced comparatively easily in particular as stamped parts made of an essentially two-dimensionally molded, i.e. original planar structure. The need for ever quieter dishwashing machines has developed over the past few years. This applies in the case of commercial dishwashing machines, particularly however in the case of household dishwashing machines. The latter is particularly justified in that a separation of kitchen and living quarters is increasingly dispensed with in modern homes.
The afore-cited dishwashing machine is disadvantageous in that it no longer fulfils the increased acoustic requirements.